I keep zooming in on the "close friendship" part...I've seen marriages last a long time based on as much.
If the fire has died down, but not causing major conflict, I'd say some councelling might be in order...
Or maybe a little something something to spice things up might help as well.

__________________
Plug me into somethin'

If the theory does not conform to the facts, then the facts must be discarded.

No good deed ever goes unpunished

Never argue with an idiot. He'll drag you down to his level, & beat you with experience.